JP5581491B2 - Golf club set - Google Patents

Description

  The present invention relates to a golf club set including golf clubs having at least three different lengths.

  Golf is a very complex game, and two rounds on the same golf course will not be the same no matter how many rounds you play, but there are some basics that always apply There are conditions.

  The possible flight distance of the ball is adjusted by the ball speed, the launch angle, and the rotation generated on the ball when hit with a golf club (ie, upon impact). The ball is similarly affected by the club speed and the kinetic energy transfer that occurs between the golf club and the ball. This means that if the ball hits are of the same kind, the club speed needs to be increased to fly the ball over long distances, and the club speed needs to be reduced to fly the ball over short distances. If a golfer should be able to hit the ball as far as possible, it is necessary to obtain a golf club that produces the highest speed while maintaining accuracy to hit the ball.

  Golf is not only about hitting the ball far away, but understanding how far the golf club carries the ball to select the right golf club to carry the ball to the desired distance when the golfer hits the ball But there is. Another factor is that the direction of the ball can be adjusted. In addition, the flight of the ball (which can adjust the rolling of the ball after it has fallen to the ground) and the different types of spin are other parameters to consider.

  Golfers are allowed to bring 14 golf clubs (at least one of which is a putter) to the course. These golf clubs have various properties that are used by golfers to try and adjust the above parameters. Prior art golf clubs are usually designed to have a 1/2 inch (12.7 millimeter) difference between iron clubs. The length of the driver is typically about 45 inches (1143 millimeters).

  Various techniques have been developed in recent years to make golf clubs feel the same for golfers.

  One technique is to balance golf clubs in a swing weight device to achieve the same swing weight for each golf club. Another technique is to design a golf club using MOI (moment of inertia), and adjusts the golf club so as to be suspended from the holding portion and causes the pendulum to move. The MOI provides a useful indication of the torsional moment for the golf club itself, and the technical objective is to achieve the same MOI for all golf clubs in the set, as disclosed in US Pat. .

Patent Document 2 describes a technique for dynamically adapting a golf club set, where the moment of inertia (I _xy ) is between clubs having various lofts that have no relationship with the length of each golf club. Can change.

  In U.S. Patent No. 6,099,059, a method for evaluating golf club sets having different lengths and lofts is disclosed. Each golf club is adapted to adjust the flight performance and distance of the golf ball.

  Club fitting can be performed to study and determine the optimal MOI for the length, direction (angle between club head and shaft), swing weight or golfer. Club fitting is performed in an advanced system that registers the movement of the ball and the golf club when hitting the ball (ie, upon impact). The goal of all club fittings is to try and provide a device suitable for the golfer that provides conditions that allow the golfer to play well.

  The basic requirement for any club fitting is that the golfer establishes muscular memory (skilled movement), for example, good golf strokes at a particular golf club. From a physical point of view, it is also important to manufacture a golf club so that the golfer can repeat the same movement of the golf club many times.

  The problem with the prior art is that although some design parameters are considered, other parameters that affect the ability to repeatedly hit the ball are not considered. How the swing changes when the golf club length changes is one parameter. Different club lengths will cause differences in stance when addressing balls in clubs having different lengths. The angle between the golfer's upper body, wrist and club varies with club length, which clearly indicates that the same swing motion cannot be achieved for golf clubs having different lengths.

US Pat. No. 5,769,733 US Pat. No. 5,351,953 US Pat. No. 6,835,143

  It is an object of the present invention to provide a golf club set adapted to compensate for changes in a golfer's swing motion for golf clubs having different lengths.

  This object is achieved by a golf club set including golf clubs having at least three different lengths. Each golf club generates at least one different torsional moment when swung by a golfer. And at least one torsional moment is essentially a linear function with respect to club length.

  An advantage of the present invention is that a golfer can handle each golf club in a golf set while taking advantage of the golfer's natural swing motion when hitting a golf ball.

  Another advantage of the present invention is that the golfer does not need to adapt the swing motion to each golf club length in the set, as in the prior art devices.

  Further objects and advantages will be appreciated by those skilled in the art from the detailed description. The present invention will be described with reference to the following drawings provided as non-limiting embodiments.

3 illustrates one embodiment of a swing action. 2 shows a graph representing the difference between the prior art consistent with MOI and the present invention. Side view of golf club (a), top view of first type club head (b), perspective view of first type club head in (b) (c), and top view of second type club head ( d) 4 shows a graph representing the movement of first and second torsional moments as a function of balance point length according to the present invention. Fig. 6 shows a graph representing the movement of the third torsional moment as a function of club head weight and club length according to the present invention. Fig. 6 shows a graph representing the movement of the fourth torsional moment as a function of club head weight and CG length according to the present invention. Fig. 4 illustrates one embodiment of four different torsional moments as a function of club length according to the present invention.

  A fundamental matter of the present invention relates to how the body affects the ability to play golf. A close analysis of the forces applied to the body when swinging a golf club reveals that muscles are divided into large and small muscle groups. Large muscles work hard, and small muscles handle fine work. During golf strokes, they work together to produce a uniform motion. In order for a golf club to be good, large and small muscle groups need to be synchronized.

  As noted above, muscle group adjustments in the prior art methods are not suitable for all golf clubs in a set in order to design or adapt a golf club. Occasionally, golf clubs, such as 7 irons, adapt very well to certain golfers, but the applicability gradually gets worse for longer and shorter clubs in the set.

The theoretical background for the inventive concept is to understand what happens and what should happen when a golfer hits the ball with a golf club. In golf, everything that happens to the moment the swing motion begins is a preparation for the golfer to perform the golf stroke as intended. These advancements include ball position, selection of applicable stroke type, golf club selection, and analysis of a series of plays. Then, the golfer moves to a position for hitting the ball, that is, takes a stance. FIG. 1 shows a golfer's swing motion 10 when hitting a ball. The swing motion starts from the top 11 and moves toward the ball 12 disposed in the bottom 13. Energy transfer between a golf club 14 and the ball 12 with a club length L _k is generated upon impact at the bottom 13.

An upper 16 of the golf club 14, the distance L _a between the rotational center 15 of swing motion is considered during the swing operation is constant, the distance is related to the length of the arm of the golfer. Arm length of the golfer (18) and the shoulder length of the socket (19) to the pivot center (15) has become a triangle, and L _a is the hypotenuse of the triangle. The swing motion depends on the variable, for example, the position of the balance point BP associated with the upper portion 16 of the golf club 14, which will be described in detail below.

The golf club includes a golf head 17 having a grip portion (not shown), a shaft (not shown), and a center of gravity CG. The CG plane is perpendicular to the central direction of the shaft and is shown in broken lines through the CG of the golf head 17 (see also the description associated with FIG. 3a). The club length L _k is defined as the distance from the top 16 to the CG plane. Club length _{L k} and the distance _{L a} is also defined in different ways, for example, from the top 16 of the golf club 14, for example, 6 inches (152.4 mm), which is the default distance on lowered grip. However, in this description, the definitions given in connection with FIGS. 1 and 3a are used.

  It should be noted that the swing motion does not end at the impact, i.e. at the bottom (13), but proceeds counterclockwise until the golfer has finished swinging. However, for clarity this is not shown in FIG.

  The golfer's muscles are loaded with energy at the top 11 to perform a golf stroke, and at the bottom 13, energy is generated for the golf stroke to be released within the muscle. As described above, muscles are divided into large muscle groups and small muscle groups. Large muscle groups are thought to be related to the golfer's torso, and small muscle groups are thought to be related to the golfer's wrist (and some extent of the arm). The golf swing is an operation accompanied by uniform acceleration from the top 1 to the bottom 13 when the golf club hits the ball 12.

  The torsional moments that the muscles need to generate are analyzed to transfer energy to the ball at the bottom, and the first torsional moments, referred to here as PCFs (plane control factors), and the ICFs (impact control factors) and here It can be divided into second torsional moments. These quantities can be expressed in mathematical formulas.

Here, L _a is (associated with arm length of the golfer) constant and, L _BP is the length of the balance point from the top 16 of the golf club 14 to the balance point BP of the golf club 14, alpha _BP Is the acceleration at the balance point BP, α _h is the acceleration at the golfer's wrist (considered to be located at the top 16 of the golf club 14), and m _k is the club weight.

  The acceleration at the balance point is expressed as follows.

Here, v _BP is the speed at the balance point, and S _BP is the distance traveled by the balance point. These are expressed as follows.

  The acceleration at the wrist is expressed as follows.

Here v _h is the velocity at the wrist, and the S _h is the distance wrist progresses. _Sh is expressed as follows.

  Equation (4) is inserted into equation (3).

  The acceleration at the wrist is expressed similarly.

  Equation (5) is inserted into equation (8), and equation (7) is inserted into equation (9), which yields:

  Equation (2) is expressed as follows.

The weight of club m _k is extracted from equation (13) and inserted into equation (1) along with equation (10a).

here,
When satisfying, the following is satisfied as described in the above formula (5).

as well as

The negative term in equation (13) can be ignored because it provides an irrelevant solution, and the balance point length L _BP can be calculated for the golf club “n” in the golf club set, PCF and ICF There given for a golf club, and L _a is determined for a golfer, (if satisfying φ _{a =} φ _h) expressed in the following equation (14).

Alternatively, the relationship between ICF and PCF for the golf club “n” can be obtained by extracting a _BP from Equation (1) and substituting it into Equation (2).

In addition to the established relationship between ICF and PCF, these quantities can also be expressed as a function of balance point length L _BP and club weight m _k . ICF is expressed by substituting the acceleration of the balance point decelerated by the acceleration of the wrist from Equation (11) to Equation (2).

  In the MOI for a golf club set, the ICF remains constant between golf clubs, but this is not the best choice due to changes in golfer swing behavior when the golf club length changes.

  Therefore, the MOI is based on the following relationship between the first golf club and the second golf club in the golf set.

This is shown in FIG. The solid line shows the MOI to meet the golf club set having a length L _k different. The torsional moment ICF is constant for each length.

  Contrary to MOI, the concept of the present invention is based on the following relationship between the first golf club and the second golf club in the golf set.

(
)

Here, α represents a linear constant, m _{k, 1} is weight, and L _{BP, 1} is the length of the balance point of the first golf club. m _{k, 2} is the weight and L _{BP, 2} is the length of the balance point of the second golf club. The torsional moment ICF according to the present invention has a solid line MOI that depends on the linear constant α value, a broken line ICF (1) with α <1 as a function of club length, and a dotted ICF (2 with α> 1 as a function of club length (2 ) Is different.

ICF (1) curves intersect at MOI curve and the first club length _{L 1,} ICF (2) curve cross the MOI curve and a second club length _{L 2,} which, according to the present invention, _{L 1} Or a club that meets the MOI having a club length equal to L ₂ represents having an ICF similar to a golf club. MOI curve each ICF curve and club length, i.e. _{L 1} of ICF (1), and it should also be noted that only intersect at _{L 2} of the ICF (2).

  PCF can be expressed by inserting the acceleration of the balance point from Equation (10a) to Equation (1).

The relationship between K ₁ and K ₂ is obtained as follows from Equation (5) on condition that φ _a = φ _h .

The torsional moment PCF according to the present invention is a linear function of the balance point length L _BP and also a function of the club length L _K. This is because the position of the balance point depends on the club head, whereby the relationship between the two golf clubs in the set is expressed as follows.

(Δ ≠ 1)

Here, δ represents a linear constant, m _{k, 1} is weight, and L _{BP, 1} is the length of the balance point of the first golf club. m _{k, 2} is the weight, or L _{BP, 2} is the length of the balance point of the second golf club, and L _a is associated with a certain length of the arm of the golfer.

FIG. 4 represents a first graph in which the movement of the first torsional moment PCF and the second torsional moment ICF is shown as a function of the balance point length and club weight according to the present invention. When L _a , K _2, and K ₃ are constant and m _k and L _BP change, the first curve 41 (broken line) shows Equation (21), and the second curve 42 (solid line) shows Equation (17). Indicates. When both equations are satisfied, the curves intersect at point 43, which is the only balance point length L _{BP, n} and corresponding club weight m _{k, n} for golf club “n”. give. This relationship corresponds to equations (15) and (16).

  Further, when the ball 12 is hit, it is desirable to control the angle of the golf club head 17 related to the swing surface and hit a straight shot. To achieve this, the angle needs to be perpendicular to the swing surface upon impact, i.e. the golf head needs to be angular. The cylindrical shaft and grip do not affect the torsional moment applied to the wrist during impact, but the club head affects the ability to control the golf club.

  The torsional moments that the muscles need to generate are analyzed to control the angle at the bottom and into a third torsional moment called HCF (head control factor) and a fourth torsional moment called GCF (gear control factor). Divided. These quantities are expressed in mathematical formulas.

Here, L _k is the golf club length, and L _CG is a sweet spot on the ball striking surface and the center of gravity CG of the golf head 17 from a point in the CG plane at the shaft center extension portion of the upper portion 16 of the golf club 14. The length to a point on the line drawn through, preferably the length of the vector to _CG , a _CG is the acceleration in CG, a _h is the wrist of the golfer (these are the top 16 of the golf club 14) _{M kh} is the club head weight.

  Figures 3a to 3d show not only various important definitions for calculating HCF and GCF, but also more detailed definitions for the length of balance points required for PCF and ICF calculations, as described above. .

Figure 3a shows a side view of a golf club 20 includes a shaft 21, the club head 23 having a grip portion 22 _g, and the center of gravity CG having a length L _g of the grip having a length L _s of the shaft. The golf club has a balance point BP and a balance point length L _BP , and the balance point length L _BP is defined in a first direction defined from the distal end 25 of the grip portion 22 along the center line of the shaft 21. Is defined as the distance to the balance point. The center of gravity CG is defined to be disposed in a plane perpendicular to the first direction (CG plane), and the club length L _k is the distance from the distal end 25 of the grip portion 22 to the CG plane along the first direction. It is prescribed. The play length L _p is the club length experienced by the golfer when swinging the golf club, and when the center of the bottom surface of the club head contacts the ground 28, the ground length (indicated by the line 28) from the distal end of the grip portion 22. ). Usually, L _p is approximately equal to L _k , except when the CG is very low (as in FIG. 3 a) or very high at the club head 23.

The club head 23 having a club head weight m _khk is provided with a hosel 26 and a hosel hole to which the shaft 21 is attached. In the present description, the position of the CG is defined with respect to the central point 27 at the top of the hosel 26 and can be expressed in the three elements L _x , L _y , and L _z . Referring to FIG. 3a, the third element _Lz is defined along a first direction from the central point 27 to the CG plane. As shown in FIG. 3b and FIG. 3c, the 1L _x and the 2L _y element is arranged in the CG plane, is defined as shown in FIG. 3b and FIG. 3c.

3b represents a top view and FIG. 3c represents a perspective view of a conventional club head 30 having a hosel 31 with hosel holes and club blades 32. FIG. The zero point 33 is represented in the hosel 31 and is defined as the point in the CG plane where the extension of the center line 24 of the shaft 21 intersects the CG plane. The L _z element is defined as the distance from the center point 38 at the top of the hosel 31, and the vector CG (horizontal bar on the letter CG in the figure: the same applies hereinafter) is defined between the zero point 33 and the vector CG. As described above, the vector CG can be divided into first L _x and second L _y elements. L _x is defined as the distance between the zero point 33 and the line 34 passing through the CG, and is perpendicular to the surface of the ball striking surface 35 of the club head 30. L _y is defined as the distance between CG and the line 36 passing through the zero point 33, and is parallel to the surface of the ball striking surface 35 of the club head 30. The point 37 at which the line 34 intersects the ball striking surface 35 is usually referred to as a “sweet spot”, and the center of gravity CG is given during the impact (at the bottom in FIG. 1) under the condition that the club head is angular. Located just behind this point. With respect to the prior of the club head, as shown in FIG. 3b, the distance from the center of gravity CG to the sweet spot 37 is longer than L _y.

FIG. 3 d shows a perspective view of the club head 40 with an offset hosel design including a hosel 41 and a club blade 42. The zero point 43 is shown in the hosel 41 and is defined as in FIG. 3b. The vector CG is defined between the zero point 43 and CG, and the vector is divided into the first L _x and second L _y elements as described above. L _x is defined as the distance between the zero point 43 and the line 44 passing through the CG, and is perpendicular to the ball striking surface 45 of the club head 40. L _y is defined as the distance between CG and the line 46 passing through the zero point 43, and is parallel to the surface of the ball striking surface 45 of the club head 40. The distance to the sweet spot 47, in the present embodiment is shorter than L _y.

In order to calculate the fourth torsional moment GCF, it is preferable that the length CG of the _CG is the length of the vector CG during the swing operation, because of the fact that the position of the CG affects the feel of the golf club. Should be noted. Alternatively, the first element L _x can be used as the length L _CG of the CG due to the fact that the CG is arranged immediately behind the sweet spots 37 and 47 at the time of impact, but the line 34 passing through the CG and the sweet spots 37 and 47 , any point 44 can be utilized as _{L CG} for calculating the GCF.

  From equations (23) and (24), it is clear that the relationship between HCF and GCF can be expressed as follows.

The CG length L _CG is expressed as follows.

According to equation (23), HCF is a function of the club length L _k , the club head weight m _kh , and the difference in acceleration between CG and wrist (a _CG −a _h ). The acceleration at the wrist is shown in the described mathematical formula (10b).

  The acceleration in CG can be calculated in the same way as the acceleration at the balance point BP when the club weight is replaced by the club head weight and the balance point length is replaced by the club length, which results in the following: .

The difference in acceleration (a _CG -a _h ) can be expressed as follows.

FIG. 5 is a graph representing the movement of the third torsional moment HCF _n as a function of the club length L _k and the club head weight m _{kh for} the golf club “n” according to the present invention because K ₂ and K ₃ are constant. Indicates. The default value of HCF _{n for} a golf club “n” provides the freedom to select the club length L _{k, n} for that golf club, which will result in the desired club head weight m _kh that will result in the desired club length L _{k, n. , N} , or a club head weight m _{kh, n} that can be selected to obtain the best head control factor.

The concept of the present invention, the golfer changes the swing by a golf club length L _k, based on the understanding that the order also changes the third torsional moment HCF. This is because it is proportional to the square of the club length, as represented by Equation (28). Therefore, it is possible to form a relationship between the first golf club and the second golf club having different lengths in the golf club set.

Here, m _{kh, 1} is the head weight, L _{k, 1} is the club length of the first golf club, m _{kh, 2} is the head weight, and L _{k, 2} is the club length of the second golf club. It is. β is usually different from 1 (β ≠ 1), but the golf club has the same HCF despite the golf clubs having different lengths, ie, L _{k, 1} ≠ L _{k, 2} It is possible to design a club set.

  Similarly, the fourth torsional moment GCF can be expressed as follows by introducing the difference in acceleration between the wrist and the CG as defined by the equations (27b) and (24).

FIG. 6 shows a golf _ball having a predetermined club length L _{k, n} as a function of _CG length L _CG and club head weight m _kh for golf club “n” according to the present invention because K ₂ and K ₃ are constant. a graph illustrating the movement of the fourth torsional moment GCF _n for the club. The default value for GCF _n relates to a golf club "n" having predetermined club length L _k, the _n results in the freedom to choose CG length L _CG for the golf _club, the _n, it is desirable CG length L _The desired club head weight m _{kh, n} , which will result in _{CG, n} , or the club head weight m _{kh, n} that may be selected, is obtained to obtain the best gear control factor.

The concept of the present invention, the golfer changes the swing by a golf club length L _k, based on the understanding that the order also changes the fourth torsional moment GCF. This is because it is proportional to the club length, as represented by equation (29). Therefore, it is possible to form a relationship between the first golf club and the second golf club having different lengths in the golf club set.

Here, m _{kh, 1} is the head weight, L _{k, 1} is the club length of the first golf club, L _{CG, 1} is the length of the CG of the first golf club, m _{kh, 2} The head weight, L _{k, 2} is the club length, L _{CG, 2} is the _CG length of the second golf club. γ is usually different from 1 (γ ≠ 1), but the golf clubs have the same GCF even if the golf clubs have different lengths, ie, L _{k, 1} ≠ L _{k, 2} It is conceivable to design a golf club set.

From equations (29) and (30), it is clear that HCF and GCF are not based on club weight m _k or balance point length L _BP for different golf clubs in the same golf club set. Similarly, from Equation (22) and Equation (19), it is clear that PCF and ICF are not based on club head weight m _kh or CG length L _CG for different golf clubs within the same golf club set. Both PCF and ICF are not based directly on the club length L _k, but one of the fundamental features of the concept of the present invention, by having a club length differentiated for at least three golf clubs in a golf club set It should also be noted that there are. This is because the swing motion changes as the club length changes.

FIG. 7 shows a graph representing the four torsional moments described above. X-axis is should represent the play length L _p of different clubs within a golf set, L _p in embodiment would be considered to be approximately equal to the club length L _k, club length L _k is used in FIG. The Y axis represents the torsional moment for PCF, HCF, ICF and GCF. When the balance point length and club weight are selected to satisfy equations (21) and (17), generally the PCF (line 71) is approximately twice as high as the ICF (line 72); This is indicated by point 43 in FIG. HCF (line 73) is usually higher than ICF and GCF (line 74) is about 1-2 percent of PCF.

  The target value of the golf club parameter can be generated from the torsional moment and the above relationship as described in the following embodiments. Two or more golf clubs are preferably prototyped under the control of the club manufacturer to determine the golf club parameters that need to establish a torsional moment slope as a function of club length. The parameter associated with the swing motion needs to be determined by measuring the parameter in a golf analyzer for a particular golfer or by using a standard value associated with the swing motion. The swing motion parameter is used for all golf clubs in the golf set even if the club length is different. Golf club parameters relate to the relationships established by Equation (19), Equation (22), Equation (29), and Equation (31).

(Main embodiment)
The following embodiments illustrate the concept of the present invention for producing a golf club set with optimal properties taking into account all four torsional moments. This is a non-limiting embodiment, and the numbers presented below vary from golfer to golfer.

7, points 61, 62, 63 and 64, respectively, PCF established for the first reference golf club with club length _{L 1,} HCF, a torsional moment about the ICF and GCF, as well as points 65 and 66, 67 and 68, respectively, PCF established with respect to the second reference golf club with club length _{L 2,} HCF, a torsional moment about the ICF and GCF. Lines 71, 72, 73 and 74 are drawn between these points and represent PCF, HCF, ICF and GCF, respectively. If three or more golf clubs are utilized as reference golf clubs, the lines 71, 74 are preferably drawn between points according to the least squares method. This means that the square of the deviation from the corresponding point on the straight line to each point is calculated, and the sum of all deviations should be as small as possible. In one embodiment, only two golf clubs are used as a reference, and straight lines 71-74 can be drawn through each point as shown in FIG. In this embodiment, the first reference golf club with club length L ₁ in the fifth metal wood, the second reference golf with club length L ₃ is a 9-iron.

Slope of straight lines 71 to 74, ie
Can be obtained by prototyping at least two golf clubs, and under the supervision of the club manufacturer, for each golf club, determine the parameters associated with the golf club, such as:

Club weight (m _k ),
Club head (L _k ),
Balance point length (L _BP ),
Club head weight (m _kh ) and CG length (L _CG )

  The golf club prototyping process also includes an analysis of the golf club's maneuverability, ensuring that the ball is hit and repeatedly moved close to the point, ie, approximately the same distance and direction. These golf clubs are used as reference clubs and determine at least two points on each line representing the torsional moment, as shown in FIG.

Furthermore, the swing parameter is necessary for the golfer to calculate each torsional moment. The swing parameters are various parameters for the golfer when swinging the club with a known club length (L _k ), namely, swing angles (φ _a , φ _h ), acceleration at the wrist (a _h ), and at the wrist Velocity (v _h ), acceleration at balance point BP (a _BP ), velocity at balance point BP (v _BP ), acceleration at club head CG (a _CG ), velocity at club head CG (v _CG ), wrist and It can be determined by measuring the distance (L _a ) between the centers of rotation. Other relevant club parameters, such as balance point length, club weight, club head weight and CG length, can be calculated from the measured values.

Alternatively, when a virtual swing robot is created that swings a virtual golf club having a predetermined club length, eg, 1000 millimeters (34.39 inches), the distance between the wrist and the center of rotation (L _a ) is, for example, 650 The club head speed has a swing motion selected as millimeters (MPH), for example, corresponding to 35.76 meters per second (m / s), for example. Further, a virtual golf club may have a default balance point length of, for example, 772 millimeters, a default club weight of, for example, 376.4 grams, a default club head weight of, for example, 255 grams, and a default CG of, for example, 38.078 millimeters. Has a length. The swing angle is selected as φ _a = φ _h = 135 °, for example, and virtual swing robot parameters, that is, a _CG , a _BP , a _h , v _BP and v _h are calculated. The numbers a _h and v _h are equal for all clubs because the virtual swing robot has the same acceleration and velocity at the wrist for golf clubs with any club length. The acceleration a _{CG at the} club head, and the acceleration and velocity at the BPa _BP and v _BP vary as a result of the calculated values for the different torsional moments, depending on changes in the length of the CG and the length of the balance point. It is described below.

PCF, ICF, HCF and GCF can be calculated for the reference club (based on the determined swing motion) using equations (1), (2), (23) and (24) respectively, so the result is , in reference to FIG. 7, represented in the graph as a function of club length L _k. In this embodiment, the virtual swing robot is used to generate a swing motion. Table 1 represents two reference clubs with club parameters and calculated torsional moments.

  The slopes for each line are as follows.

The target values for PCF, HCF, ICF and GCF are calculated when the golf club length (L ₃ ) is selected, for example L ₃ = 965 millimeters for a 5 iron. The following target values for the torsional moment are calculated using the above inclination.

PCF (L ₃ ) = 45.732
HCF (L ₃ ) = 19.777
ICF (L ₃ ) = 17.291
GCF (L ₃ ) = 0.684

  The target values 75, 76, 77 and 78 are each indicated by a black circle on each straight line, and the maximum deviation from each target value is also indicated.

  The actual PCF value of the resulting golf club can vary between dotted lines 81, which is preferably less than ± 0.5% of the target value 75, more preferably ± 0. The deviation is attributed to less than 2%. The actual HCF value of the resulting golf club can vary between lines 82, but it is preferably less than ± 1% of the target value 76, more preferably ± 0.5% of the target value 75. Attribute to a smaller deviation. The actual ICF value of the resulting golf club can vary between dotted lines 83, which is preferably less than ± 1% of the target value 77, more preferably ± 0.5% of the target value 75. Attribute to a smaller deviation. The actual GCF value of the resulting golf club can vary between lines 84, but it is preferably less than ± 5% of target value 78, more preferably less than ± 2% of target value 75. Return to deviation.

  In addition, target values for several golf club parameters, such as club weight, balance point length, golf head weight and CG length, can also be obtained when torsional moments and golf club parameter values are selected when the club length is selected. Calculated as shown in Table 2 using the relationships established between them. Table 2 below shows the target values for a 5 iron with club length = 965 millimeters.

  The golf club of No. 5 iron is assembled with related elements such as a shaft, a club head, and a grip, and has an actual value that is close to the target value. The actual value is then used to calculate the torsional moment using equations (1), (2), (23) and (24). Actual values and calculated torsion values are shown in Table 3. Table 3 below shows actual values and calculated torsional moments for a # 5 iron with club length = 965 millimeters.

  It should be noted that even though the actual club parameter is equal to the target value for the club parameter, the target value for the torsional moment is different from the calculated value. This is because the calculated torsional moment is calculated from the actual club parameters and the desired torsional moment is obtained from the straight line generated by the reference club.

The club weight m _k is the sum of the club head weight m _kh , the shaft weight m _s, and the grip weight _mg .

Further, the balance point length L _BP is the grip balance point length L _{BP, g} , grip weight _mg , shaft balance point length L _{BP, S} , shaft weight m _s , club length L _k , club head _Determined by weight m _kh and club weight m _k . Delta _g is the thickness of the grip end, usually about 5 millimeters.

  The grip portion is preferably a standard grip having a known, predetermined weight and balance point length, club weight, club length, balance point length and club head weight. The weight of the shaft and the length of the shaft balance point can be determined from equations (32) and (33). Table 4 below shows the actual parameters for a 5 iron golf club (= 5 millimeter) element.

  The swing weight for the assembled 5 iron can be calculated using the swing weight equation.

  The swing weight for the assembled 5 iron is 217.5 (ounces) and corresponds to D2.3 in the swing weight table.

  The golf club set naturally includes three or more golf clubs, and the seven golf clubs (3 iron to 9 iron) in the following example are manufactured based on the straight lines 71 to 74 representing the torsional moment. . The following target values are obtained. Table 5 below shows the target values for the No. 3 iron to No. 9 iron based on the reference club in Table 1 described above. The target torsional moment is represented without an acceptable deviation.

  The length difference between each golf club is about ½ inch (12.7 millimeters), and the head loft increases as the club length decreases throughout the set. Traditionally, club head weight increases by 7 grams for every 1/2 inch of length. However, as apparent from Table 5, the head weight in the golf club set according to the present invention has a fixed weight difference every 1/2 inch. The head weight difference between 3 and 4 irons is 7.5 grams, while the head weight difference between 8 and 9 irons is 9.8 grams. Further, the CG length is not constant for golf clubs in the set and increases as the golf club length decreases. Club head weight differences and CG length differences are obtained and varied by each golfer individually.

  If the grip weight and grip balance points are equal for the golf clubs in the set, the following golf club parameters are obtained. Table 6 below shows the actual parameters for the elements from 3 iron to 9 iron club (= 5 millimeters).

  Even if the total weight of the golf club is increased using a short club length, the shaft weight is rather constant for long clubs (3 irons, 4 irons and 5 irons) and short clubs (7 It should be noted that the number of irons, irons 8, and 9 is gradually decreasing. In short clubs, the length of the shaft balance point decreases gradually, and in short clubs the swing weight gradually increases.

  Iron clubs are used to illustrate the concepts of the present invention, but it is of course possible to design other types of golf clubs such as metal wood, drivers, wedges and putters using similar procedures.

  The first torsional moment (ie PCF) is the load affecting the golfer at the center of rotation 15 in FIG. 1, and the second, third and fourth torsional moments (ie ICF, HCF and GCF) are the wrist 16 in FIG. It should be noted that this is a load that affects golfers.

  Since each torsional moment is applied to the golf club set, it is used independently for the user. However, it should be noted that each torsional moment is not independent of the other torsional moments as is apparent from the above equation. Any change in torsional moment with respect to the golf club will affect one or more additional torsional moments. Four embodiments are shown below to highlight each torsional moment.

(PCF)
The plane control factor (PCF) is a function of the club weight m _k , the balance point length L _BP, and the constant L _a (related to the length of the golfer's arm), as is apparent from equation (21). A golf club set in which each golf club has a predetermined length can be adjusted by changing the length of the balance point and the club weight of the short golf club to determine a suitable PCF for the short club, which is the golfer's swing surface And obtained when the velocity at impact is constant. A similar procedure is repeated for longer golf clubs to determine a suitable PCF for longer golf clubs. A straight line with a slope is drawn between two PCF values as a function of club length. The club weight and balance point length can be adjusted based on the remaining golf clubs in the set.

  PCF is preferably combined with an impact control factor (ICF), which is a function of club weight and balance point length, as is apparent from equation (17). The PCF combined with the ICF produces the best balance point length and club weight for the default PCF and default ICF, as is apparent from the description in FIG. 5 and equation (13).

(ICF)
The impact control factor is a function of the club weight and the length of the balance point, as is apparent from Equation (17). A golf club set in which each golf club has a predetermined length can be adjusted by changing the balance point length and the club weight of the short golf club to determine a suitable ICF for the short club, which is the feel of the golf head. And obtained when the wrist function through the swing is stable. A similar procedure is repeated for longer golf clubs to determine a suitable ICF for longer golf clubs. A straight line with a slope is drawn between two ICF values as a function of club length. The club weight and balance point length can be adjusted based on the remaining golf clubs in the set.

The ICF is preferably combined with a planar control factor (PCF), but as is clear from equation (21), the PCF is the club weight m _k , the balance point length L _BP and the constant L _a (the length of the golfer's arm). (Related to). The ICF combined with the PCF produces the best balance point length and club weight for the default PCF and default ICF, as is apparent from the description in FIG. 5 and Equation (13).

(HCF)
As is clear from Equation (28), the head control factor is a function of the club length L _k and the club head weight m _kh . A golf club set in which each golf club has a predetermined length can be adjusted by changing the length of the balance point and the club weight of the short golf club to determine a suitable HCF for the short club, which is the impact on the ball Is obtained when it is stable in the club head. A similar procedure is repeated for longer golf clubs to determine a suitable HCF for longer golf clubs. A straight line with a slope is drawn between two HCF values as a function of club length. The club weight and balance point length can be adjusted based on the remaining golf clubs in the set.

HCF is preferably combined with a gear control factor (GCF), but as is apparent from equation (30), PCF is a function of club length L _k , CG length L _CG and club head weight m _kh . The HCF combined with the GCF produces the best CG length for the default HCF and the default ICF, as is apparent from equation (25).

(GCF)
The impact control factor is a function of the club weight and the length of the balance point, as is apparent from Equation (17). A golf club set in which each golf club has a predetermined length can be adjusted by changing the CG length of the short golf club to determine a suitable GCF for the short club, which stabilizes the feel of the golf head, Obtained when the golfer can stably move the ball (draw / fade control) and the golfer can stably control the head angle associated with the swing surface. A similar procedure is repeated for longer golf clubs to determine a suitable GCF for longer golf clubs. A straight line with a slope is drawn between two GCF values as a function of club length. The club weight and balance point length can be adjusted based on the remaining golf clubs in the set.

GCF is preferably combined with a head control factor (HCF), but as is apparent from equation (28), HCF is a function of club length L _k and club head weight m _kh . The GCF combined with the HCF produces the best CG length for the default GCF and the default HCF, as is apparent from equation (26).

  When designing a golf club set, it is more preferred to combine all four torsional moments, as shown above in connection with the description of Tables 1-6, but the invention should not be limited to this . Each described torsional moment improves upon a conventional golf club set.

An important feature of the present invention is not to obtain a lower / higher torsional moment than in the prior art, but to allow the golfer to load appropriately and repeat the same swing action many times (to obtain an appropriate response) This is to maximize the golfer's potential in golf.

Claims (18)

At least three golf clubs of sets with different club length L _k, each golf club (14, 20) is a shaft having an upper end and a lower end (21), the grip portion (22) and the in the upper end of the shaft a head (23,30,40) including a ball striking surface that is mounted on the lower end of the shaft, said club length L _k of the respective golf club sequentially decreases from the longest ones, each golf club the In a set of golf clubs having a balance point length L _{BP, n} and a club weight m _{k, n} defined as a balance point BP from the distal end of the grip portion,
Each of the golf clubs is designed based on at least two torsional moments (I CF _n , PCF _n ) of each of the at least three golf clubs when swung by a golfer ;
Each of the golf clubs _n has a balance point length L _{BP, n} and a club weight m _{k, n} ,
A set of golf clubs characterized by
(Wherein, PCF _n first torsional moments at the pivot center (15) with respect to the golfer's swing motion relative to each golf club _n, ICF _n second torsion in the wrist of the golfer with respect to each of the golf club of the at least three moment, a _h is a constant to represent the golfer's acceleration wrist when hitting the ball, the L _a is a constant related to the length of the arm of the golfer, further wherein said first and each golf club _n second torsional moment _PCF n, at least one value of ICF _n (61,65,75; 63,67,77) are different from each other, and the first and second torsional moment _PCF n, ICF _n's each golf club the primary function of club length _{L k} that have a relationship shown in (71, 73)) Wherein the first torsional moment PCF for each golf club n is in the club weight m _{k, n,} the length L _BP of the balance _point, the function of the constant L _a related to the length of the arm of _n and golfers, The set of golf clubs according to claim 1 satisfying the following formula.
Wherein said at least three first golf club of the golf club and the second golf club of the golf club of the at least three have relevance, satisfy the following formula, a set of golf clubs according to claim 2.
(Δ ≠ 1)
_{(Wherein, m k, 1} is the _{weight, L BP, 1} is the balance point length of the first golf _{club, m k, 2} is the _{weight, L BP, 2} is the second golf club a balance point length, and L _a is a constant related to the length of the arm of the golfer) The second torsional moment of each golf club n is the club weight m _{k, n} and the balance point length L _BP, a function of _n, satisfies the following formula, according to any one of claims 1 to 3 Golf club set.
5. The set of golf clubs according to claim 4, wherein the first golf club of the at least three golf clubs has a relationship represented by the following formula with respect to the second golf club of the at least three golf clubs .
(Α ≠ 1)
_{(Wherein, m k, 1} is the _{weight, L BP, 1} is the balance point length of the first golf _{club, m k, 2} is the _{weight, L BP, 2} is the second golf club which is the balance point length) Each golf club n has a club head weight m _{kh, n} having a center of gravity CG arranged in a plane perpendicular to the first direction along the center of the shaft, and the club length L _{k, n} is the grip portion Is defined as a first distance from the distal end of the golf club to the plane along a first direction, and each golf club generates a third torsional moment HCF _n for each golf club when swung by a golfer. 6. The golf club according to claim 1, wherein the third torsional moment is proportional to a product of the squares of the club head weight m _{kh, n} and the club length L _{k, n} and satisfies the following formula . set.
The set of golf clubs according to claim 6, wherein a first golf club of the at least three golf clubs has a relationship represented by the following formula with respect to the second golf club of the at least three golf clubs .
(Β ≠ 1)
( _Where m _{kh, 1} is the head weight, L _{k, 1} is the club length of the first golf club, m _{kh, 2} is the head weight, and L _{k, 2} is the second golf. The club head of the club ) Wherein each golf club n is, when it is swing the golfer, said for at least three respective golf club, the fourth torsional moment GCF has a relationship represented by the following formula with respect to the third torsional moment HCF _n The set of golf clubs according to claim 6 or 7, which generates _n .
(Wherein, HCF _n in the third torsional moment, GCF _n is the club length _{L k, n} and the CG length _{L CG,} in the fourth torsional moment for a golf club with a _n, the length of the CG From a zero point located in the plane and in the shaft center extension along the first direction in the plane,
The center of gravity CG, or the distance to any one on the line that passes through the ball hitting surface and the sweet spot on the center of gravity CG ) Each golf club n has the club head weight m _{kh, n} with the center of gravity CG arranged in a plane perpendicular to the first direction along the center of the shaft, and the club length L _{k, n} is the is defined as a first distance from the distal end of the grip portion to the plane along the first direction, wherein the fourth torsional moment GCF _n at least two torsional moment for each golf club, the fourth The torsional moment is proportional to the product of the club head weight m _{kh, n} , the CG length L _{CG, n} and the club length L _{k, n} ,
The length of the CG is from the zero point located in the plane and extending in the center of the shaft along the first direction in the plane.
The set of golf clubs according to any one of claims 1 to 5, which represents a distance to the center of gravity CG or a point on a line passing through a sweet spot on the ball hitting surface and the center of gravity CG. The set of golf clubs according to claim 9, wherein a first golf club of the at least three golf clubs has a relationship represented by the following formula with respect to the second golf club of the at least three golf clubs .
(Γ ≠ 1)
( _Where m _{kh, 1} is the head weight, L _{k, 1} is the club length, L _{CG, 1} is the length of the CG of the first golf club, m _kh, Head weight, L _{k, 2} is the club length, L _{CG, 2} is the CG length of the second golf club ) Wherein each golf club n is when it is swing the golfer, said for at least three respective golf club, the third torsional moment HCF has a relationship represented by the following formula with respect to the fourth torsional moment GCF _n The set of golf clubs according to claim 9, wherein _n is generated.
(Wherein, HCF _n is the third torsional moment, GCF _n is the fourth torsional moment for a golf club n with the club length _{L k, n} and length _{L CG, n} of the CG, the The length of the CG is disposed in the plane, and the center of gravity CG or the ball striking surface from the zero point in the shaft center extension portion along the first direction in the plane. And the distance to any point on the line passing through the sweet spot on the center of gravity CG ) 12. A set of golf clubs according to any one of the preceding claims, wherein the loft of the head increases through the set and the length of the golf club decreases through the set as the loft of each head increases. Each of the linear functions (71, 72, 73, 74) of the club length L _{k, n} has a target value for each of the at least three golf clubs and a deviation of a predetermined numerical value or less from each target value. defines the values of at least two torsional moments on the golf club, a set of golf clubs according to any one of claims 1 to 12. Said through at least two of at least one torsion said value of moment (61,65,62,66,63,67,64,68) a linear function (71, 72, 73, 74) is for said golf club ,
The linear function is based on a least squares method of the values (61, 65, 75, 62, 66, 76, 63, 67, 77, 64, 68, 78) of at least one torsional moment for the golf club. A set of golf clubs according to any one of 1 to 13. Shaft weight m _{s, n} And balance point length L _{BP, s, n} Wherein the shaft is configured for use in a golf club set as defined in any one of claims 1 to 15, wherein the shaft weight is:
(Where m _{k, n} Is the total weight of the golf club, m _{g, n} Is the grip weight attached to the golf club, m _{kh, n} Is the club head weight)
And balance point length L _{BP, s, n} Is
A golf club shaft characterized by being:
(Where L _{BP, g, n} Is the length of the balance point of the grip, m _{g, n} Is the grip weight, L _{BP, n} Is the length of the balance point of the club, m _{k, n} Is the club weight, m _{s, n} Is the shaft weight, L _{k, n} Is the club head and m _{kh, n} Is the club head weight and the grip end thickness is Δ _g Is) In the golf head for a golf club _n, the golf head club head weight m _kh having the center of gravity CG arranged in a plane perpendicular to the first direction along the center of the _shaft, the golf head having _n the golf head, wherein the is configured to be used in Lugo Ruch club set as specified in any one of claims 1 to 15 Turkey. Before chrysanthemum Love head weight _{m kh, n} is the club length _{L k, n} and the CG length _{L CG,} proportional to the product of _n,
The length before Symbol CG, the are arranged in a plane, and, in the plane, from zero point is in the said shaft central extension along the first direction,
The golf head according to claim 16, which represents a distance to either the center of gravity CG or a point on a line passing through a sweet spot on the ball hitting surface and the center of gravity CG. The golf head according to claim 17, wherein the first golf club of the at least three golf clubs has a relationship represented by the following formula with respect to the second golf club of the at least three golf clubs.
_{(Wherein, m kh, 1} is the head _{weight, L k, 1} is the previous chrysanthemums Love length, _{L CG, 1} is the length of the CG of the first golf club, _{m kh, 2} a the head weight, L _{k, 2} is Ri before listen Love length der, L _{CG, 2} is the length of the CG of the second golf club, gamma is Ru inclined der primary function)